Electrical measuring instrument.



No. 7o0,m. Patented May l3, I902.

V. ARCIUNI. ELECTRICAL MEASURING INSTRUMENT.

(Application flied July 25', 1901.)

(No Model.)

bfrzyerzwfar THE Nonm's PETERS co. PHOTO-L|THO.. WASHWGTON, a c.

UNITED STATES PATENT OEEIcE.

VITTORIO ARCIONI, OF SPOLETA, ITALY, ASSIGNOR TO CAMILLO OLIVET'II,

' OF IVREA, ITALY.

lNSTRUMENT.

SPEGIFICATIGN forming part of Letters Patent No. 700,1 1 1, dated May13, 1902.

Application filed July 25,1901.

To all whom it may concern:

Be it known that I, VITTORIO AROIONI, a subject of the King of Italy,residing at Spoleta, Italy, have invented certain new and usefulImprovements in Electrical Measuring Instruments, of which the followingis a specification.

My invention relates to electrical measur ing instruments of that classin which a movable part acted upon by the current to be measured isnormally maintained at the zeropointbyacounterbalancing force whichtends to neutralize the effect of the current on said movable part,which counterbalancing force is measured and gives the value of thecurrent.

One of the chief objections to this class of inventions heretofore isthat direct readings of the energy, potential, or other value of thecurrent to be measured cannot be obtained.

The object of my invention is to provide improved means whereby a directvisual indication of a record may be obtained of the value of thecurrent flowing in this class of instruments.

A further object of the invention is to provide a counterbalancingdevice for equalizing the action of the current on the movable partofthe instrument and normally maintaining the same at the zero -point,novel means thrown into operation by said movable part for increasing ordecreasing the tension of said counterbalancing device, and means formeasuring the force exerted on said counterbalancing device.

A further object of the invention is to provide a motor having a noveladjustable connection with said counterbalancing device, means forautomatically throwing said motor into operation in one direction or theother for increasing or decreasing the tension of said counterbalancingdevice, and indicating mechanism connected with said motor.

Other objects and advantages of the invention will hereinafter appear,and the novel features thereofwill be set forth in the claims.

In the drawings forming part of this specification, Figure 1 is a viewshowing my improvements in elevation in connection with a wattmeter.Fig. 2 is a diagrammatic view showing the circuit connections betweenthe Serial No. 69,725. kNo model.)

line, the motor, the field-coils of the meter, and the armature thereof;and Fig. 3 is a diagrammatic view showing a modified arrangement inwhich the circuit connections through the motor lead from a source ofcurrent independent of the line.

Like reference-numerals indicate like parts in the different Views.

lVhile my invention has been illustrated as a wattmeter, I desire to beunderstood that the same is adapted for use without material change withany form of electrical measuring instrument.

The field-coils 1 and 2 are connected in series with the leg 3 of theline 3 4; through the wires 5, 6, and 7. The armature 8 is in shunt orparallel with the line 3 4 through the wires 9 and 10, the latterpreferablyincluding a resistance 11. The armature 8 constitutes themovable part of the meter and is capable of vibration upon a centralpivot or support, due to the action of the current thereon. Connectedwith, but insulated from, the movable part 8 is a rod 12, of conductingmaterial, which is movable between and adapted to'forin electricalcontact with the contacts 13 and ll. These contacts are located veryclose together, so that the slightest movement of the rod 12 in onedirection or the other will cause the engagement of the same with one orthe other of said contacts. Secured to the movable part 8 and extendingoutwardly therefrom is an arm 15, to which is attached one end of aspring 16, constituting the counter-balancing device, as willhereinafter appear. The end of the arm 15 opposite that to which thespring 16 is attached is provided with an adjustable weight 17 for anobvious purpose. The spring 16 is connected at its opposite end to aninternally-threaded collar or nut 18, mounted upon a threaded shaft 19,connected with, driven from, or forming part of the armature-shaft ofthe motor 20. The collar or nut 18 is incapable of turning movement onthe shaft 19; but when said shaft rotates in one direction or the otherthe said collar or nut will be moved longitudinally thereof in onedirection or the other. The

motor 20 has been shown as a rotary electric motor; but any othersuitable form of motor may be substituted for the same-that is to IOOsay, a mechanical motor may be employed in place of the electric motor,or a reciprocating or other motor may be substituted for the retarymotor, and even when the motor 20 is an electric motor it may be soconstructed as to be operated by either a direct or alternating current.It is necessary, however, that said motor be capable of ready reversal,and it is important that it be so constructed that no dead-centers canoccur. For the spring 16, which constitutes the eounterbalancing device,I may also substitute a counterbalancing-weight or other equivalentmechanism. Connected with the collar or nut 18 is a pencil, pen, orother marking device 21, which lies in contact with a rotating drum orcylinder 22, the said marking device and the said cylinder constitutingthe recording mechanism for registering the movements of the collar 18.Secured to the shaft 19 is a worm 23, and meshing with said worm is aWorm- Wheel 24, which carries an indicating hand or pointer 25, whichmoves in front of a dial 20.

WVhen no current is flowing through the instrument, the counterbalancingdevice 16 is so adjusted with respect to the armature 8 that the latteris maintained at the zeropoint, and the rod 12, carried by the armature8, is maintained at a point between the two contacts 13 and 14:. Thisadjustment may be effected by means of the weight 17 on one end of thearm 15 or in any other suitable way. Now upon the passage of currentfrom the line 3 4: through the instrument the tendency will be todeflect or turn the armature 8 in one direction or the other. Thistendency of the armature or moving part 8 to turn will be resisted bythe stress or tension of the counterbalancing device 16, which in theform shown in the drawings isa spring. The force required to be exertedon the spring 16 to return the armature or moving part 8 to its zeroposition will be equivalent to the energy or other value of the currentto be measured, and by determining this force the energy or other valueof the current is determined. By moving the collar 18, to which thespring 10 is attached, toward the motor 20 an increased tension is givento the spring 16, and the extent of movement of said collar 18 toovercome the action of the current on the moving part 8 Will beproportional to or have a definite ratio to the energy or other value ofthe current to be measured. As this movement of the collar or nut 18 isobtained by the rotation of the shaft 19 and as said shaft is connectedthrough the worm 23 and worm-wheel 24 with the hand or pointer 25, avisual indication on the dial 26 will be given by said hand 25, whichwill indicate the value of the current. As the pencil or other markingdevice 21 is directly connected with the collar or nut 18 and moves overthe face of the drum or cylinder 22, a record of the value of thecurrent flowing through the instrument will also be made by therecording mechanism.

To provide for the automatic rotation of the shaft 19 in one directionor the other to compensate for variations in the energy or other valueof the current flowing through the instrument, I provide a normallyclosed shuntcircuit from the line, consisting of the wire 27, thefield-magnet 28 of the motor 20, the wire 29, the non-inductiveresistance-coils and 31, and the wire 32. Leading from the contact-point11 to the wire 82 at a point above the resistance-coil 81 is a wire 33,and leading from the contact-point 13 to the wire 29 at a point belowthe resistance-coil 30 is a Wire 31. Leading from a point between theresistance-coils 2-30 and 31 is a wire 85, which through the brushes 86and the commutator connects with the armature 8/ of the motor 20, andconnecting said armature with the rod 12 is aflexible wire 38. \Vhenthere is a potentialon the main line 3 1-, there will beaflowof currentthrough the normally closed shuntcircuit above traced, which includesthe field magnet 28 of the motor and the resistancecoils 30 and 31. As aresult the said fieldmagnet 28 will be constantly energized and therewill be a difference of potential between the ends of boththe'resistance-coils 80 and 31. lVhenever the field-coils 1 and 2 areenergized by the flow of current from the line therethrough, the movablepart 8 will be turned against the action of the counterbalancing device1Gsay in the direction of retation of the hands of a clock. This willbring the conducting-rod 12 into engagement with the contact 18 andclose a secondary circuit through the armature 37 of the motor 20 overthe following course, the current-flow being due to the difference ofpotential at the ends of the resistance-coil 30: wire 31, contactpoint13, rod 12, wire 38, brushes 36, armature 37, and wire to the oppositeend of coil 30. The motor 20 is thereby thrown into operation in onedirection and rotates the shaft 19, so as to draw the collar or nut 18toward the motor and increase the tension of the counterbalancing deviceor spring 10. The operation of the motor in this direction continuesuntil the collar or nut 18 has been moved to such a point that theincreased tension of the spring 10 will overcome the action of'thecurrent on the armature or moving part 8 and restore the latter to itsnormal zero position. W'hen this is done, the rod 12 will occupy aposition between the contacts 13 and 121- and the circuit just tracedthrough the armature of the motor will be broken. The result is that themotor will be thrown out of operation and the shaft 19 cease to rotate.The extent of movement of the spring 10 will be recorded by the pencil21 on the rotating drum 22, and the degree of movement of the shaft 19,which will bear the same ratio to the extent of movement of the spring16, will be indicated by the hand or pointer25 on the dial 20. Theindicating and recording devices will visually show and mechanicallyregister the energy or other value of the current IIO flowing throughthe instrument. Now it the energy or other value of the current to bemeasured increases the armature 8 will be again turned against theaction of the spring 16 in the same direction as before and contactagain made between the conducting-rod 12 and the contact-point 13. Theresult of this will be that the motor 20 will be again operated in thesame direction as before, so as to increase the tension of thecounterbalancing device 16 to such an extent as to re turn the movingpart 8 to its normal zero position and the rod 12 to its normal positionbetween the contacts 13 and 1%. If, however, the energy of the currentto be measured decreases, the force exerted by the counterbalancingdevice 16 will be greater than that exerted by the current on thearmature or moving part 8. In consequence the armature or moving part 8will be moved by the counterbalancing device 16 in a directionoppositeto that of the movement of the hands of a watch, and the conducting-rod12 will be moved to the right, so as to be brought into engagement withthe contact-point let. A new secondary circuit is then closed throughthe armature 37 of the motor over the following path: wire 35, brushes36, armature 37, wire 38, and rod 12 to contact-point 14, and thencethrough wire 33 to the opposite side of resistance-coil 31. The currentthrough this circuit is supplied by reason of the difference ofpotential at the ends of the coil 31. It will be noted that the circuitthrough the field-magnet 28 is in the same direction as it was when theenergy of the current was onthe increase, but that the flow of currentthrough the armature 37 is directly opposite that through which itpassed when the energy of the current was on the increase. As a resultthe motor 20 is reversed and the shaft 19, operated thereby, is turnedin a direction opposite to that at which it was formerly turned. Thecollar or nut 18 is therefore moved away from the motor 20 and thetension of the spring 16 or other counterbalancingdevicerelieved.WVhenthetension of the spring 16 has been sufficiently relieved, so thatthe same just counterbalances the action of the current on the armatureor moving part 8, the said armature or moving part is returned to itsnormal zero position, and the rod 12 is moved to a point between thecontacts 13 and 14.. This movement of the collar or nut 18 and of theshaft 19, which carries the Worm 23, will be recorded on the cylinder 22and indicated by the hand or pointer 25 on the dial 26.

It will thus be seen that according to my invention means are providedfor normally maintaining the armature or other movable part of the meterat its zero-point, the variable force necessary for this purpose beingthe force which is measured and being equivalent to the energy or othervalue of the current to be measured. It will also be noted that throughthe action of the movable part 8 of the motor the motor which controlsthe tension of the counterbalancing device is automatically thrown intoand out of operation and reversed. It will also be noted that means areprovided in an instrument of this kind for providing a visualindication, as well as a record of the energy or other value of thecurrent flowing through the instrument.

According to the construction shown in Figs. 1 and 2 of the drawings themotor is actuated by the current taken directly from the line, theenergy or other value of which is to be measured. Instead of taking thecurrent from the line and passing the same through the motor 20 in onedirection or the other said motor may be actuated from an independentsource of supply of electric current. An arrangement by which this maybe done is illustrated in Fig. 3 of the drawings, in which a battery 39is shown, having one pole connected with the contact-point 13 through awire 3a and the other pole connected with the contact-point 1% throughthe wire 33. The conducting-rod 12, which is connected, as before, withthe armature or movable part of the meter, is located between thecontacts 13 and 1 1 and is connected through the wire 38 with thearmature 37 of a dynamo-electric motor 20. From the armature S7 leads awire 35 to the battery 39. The operation of this form of my invention issimilar to that described and needs no detail description. It issufficient to say that when contact is made between the rod 12 and thecontactpoint 18 the current flows from the battery 59 through thearmature 37 of the motor 2O in one direction to operate the motor, andwhen contact is made between the rod 12 and the contactpoint 1% thecircuit is closed through the armature P7" of the motor 2O in theopposite direction, reversing the motor. The connections between the rod12 and those between the motor 20 and the other parts of the device aresimilar to those described with reference to the construction shown inFig. l of the drawings.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. In an electrical measuring instrument, a movable part acted upon bythe current, a counterbalancing device for equalizing the 'action of thecurrent thereon, a shaft and means movable longitudinally of said shaftfor automatically increasing and decreasing the tension of saidcounterbalancing device on said movable part.

2. In an electrical measuring instrument, a movable part acted upon bythe current, a counterbalancing device for equalizing the action of thecurrent thereon, a shaft and means movable longitudinally of said shaftand thrown into operation by an increase or decrease in the energy orother value of the current to be measured for increasing and decreasingthe tension of said counterbalancing device on said movable part.

o. In an electrical measuringinstrument, a

Lil

movable part acted upon by the current, a counterbalancing device forequalizing the action of the current thereon, a shaft, means movablelongitudinally of said shaft for antomatically increasing and decreasingthe tension of said counterbalancing device on said movable part, andmeans for indicating the force exerted on said counterbalancing device.

4. In an electrical measuringinstrument, a movable part acted upon bythe current, a counterbalancing device for equalizing the action of thecurrent thereon, a shaft, means movable longitudinally of said shaft forantomaticallyincreasing and decreasing the tension of saidcounterbalancing device on said movable part, and means for continuouslyrecording the force exerted on said counterbalancing device.

5. In an electrical measuring instrument, a movable part acted upon bythe current, a counterbalancing device for equalizing the action of thecurrent thereon, a shaft, means movable longitudinally of said shaft forantomaticallyincreasing and decreasing the tension of saidcounterbalancing device on said movable part, means for indicating theforce exerted on said counterbalancing device, and means forcontinuously recording said force.

6. In an electrical measuring instrument, a movable part acted upon bythe current, a counterbalancing device for equalizing the action of thecurrent thereon, a motor, a retary shaft operated thereby, alongitudinallymovable connecting device actuated by said shaft andattached to said counterbalancing device for increasing and decreasingthe tension thereof, and means thrown into operation by said movablepart for operating said motor in one direction or the other, accordingas the energy or other value of the current increases or decreases.

7. In an electrical measuring instrument, a movable part acted upon bythe current, a counterbalancing device for equalizing the action of thecurrent thereon, a motor, a retary shaft operated thereby, alongitudinallymovable connecting device actuated by said shaft andattached to said counterbalancing device for increasing and decreasingthe tension thereof, means thrown into operation by said movable partfor operating said motor in one direction or the other, according: asthe energy or othervalue of the current increases or decreases, and anindicating device connected with said motor and operated thereby.

8. In an electricalmeasuringinstrument, a movable part acted upon by thecurrent, a counterbalancing device for equalizing the action of thecurrent thereon, a motor, a rotary shaft operated thereby, alongitudinally-movable connecting device actuated by said shaft andattached to said counterbalancing device for increasing and decreasingthe tension thereof, means thrown into operation by said movable partfor operating said motor in one direction or the other, according as theontoo,

ergy or other .value of the current increases or decreases, and arecording device connected With said motor and operated thereby.

9. I11 an electrical measuring instrument, a movable part acted upon bythe current, a counterbalancing device forequalizing the action of thecurrent thereon, a motor, a rotary shaft operated thereby, alongitudinally-movable connecting device actuated by said shaft andattached to said counterbalancing device for increasing and decreasingthe tension thereof, means thrown into operation bysaid movable part foroperating said motorin one direction or the other, according as theenergy or other value of the current increases or decreases, anindicating device, and a recording device, both connected with saidmotor and operated thereby.

10. In an electrical measuring instrument, a movable part acted upon bythe current, a counterbalancing device for equalizing the action of thecurrent on said movable part, a motor for increasing and decreasing theten sion of said counterbalancing device,a threaded shaft connected withand operated by said motor, a threaded nut or collar on said shaft,movable longitudinally thereof and having said counterbalancing deviceconnected with it, and means thrown into operation by said movable partfor starting said motor in one direction or the other, according as theenergy or other value of the current to be measured increases ordecreases.

11. In an electrical measuringinstrument, a movable part acted upon bythe current, a counter-balancingdevice forequalizing the action of thecurrent on said movable part, a motor for increasing and decreasing thetensionofsaid connterbalancing device,a threaded shaft connected withand operated by said motor, a threaded not or collar on said shaft,movable longitudinally thereof and having said counterbalancing deviceconnected with it, means thrown into operation by said. movable part forstarting said motor in one direction or the other, according as theenergy or other value of the current to be measured increases ordecreases, and an indicating device connected with, and operated by,said shaft.

12. In an electrical measuring instrument, a movable part acted upon bythe current, a counterbalancing device for equalizing the action of thecurrent on said movable part, a motor for increasing and decreasing thetension ofsaid counterbalancingdevice,a threaded shaft connectedwith,and operated by, said motor, a threaded nut or collar on saidshaft, movable longitudinally thereof and having said counterbalancingdevice connected with it, means thrown into operation by said movablepart for starting said motor in one direction or the other, according asthe energy or other value of the current to be measured increases ordecreases, and a recording device connected with, and operated by, saidshaft.

13. In an electrical measuring instrument,

IIO

a movable part acted upon by the current, a counterbalancing device forequalizing the action of the current on said movable part, a motor forincreasing and decreasing the tensionof said eounterbalancingdevice,athreaded shaft connected with, and operated by, said motor, athreaded nut or collaron said shaft, movable longitudinally thereof andhaving said counterbalancing device connected with it, means thrown intooperation by said movable part for starting said motor in one directionor the other, according as the energy or other value of the current tobe measured increases or decreases, a worm secured to said shaft, aworm-wheel meshing therewith, and an indicating hand or pointer carriedby said worm-wheel.

lat. In an electrical measuring instrument, a movable part acted upon bythe current, a counterbalancing device for equalizing the action of thecurrent on said movable part, a motor for increasing and decreasing thetension ofsaid counterbalancing device,athreaded shaft connected with,and operated by, said motor, a threaded nut or collar on said shaft,movable longitudinally thereof and having said counterbalancing deviceconnected with it, means thrown into operation by said movable part forstarting said motor in one direction or the other, according as theenergy or other value of the current to be measured in creases ordecreases, a rotating drum or cylinder, and a marking device carried bysaid collar or nut and bearing against said drum.

15. In an electrical measuring instrument, a movable part acted upon bythe current, a counterbalancing device for equalizing the action of thecurrent on said movable part, a motor for increasing and decreasing thetension of said counterbalancing device, a threaded shaft connectedwith, and operated by, said motor, a threaded nut or collar on saidshaft, movable longitudinally thereof and having said counterbalancingdevice connected with it, means thrown into operation by said movablepart for starting said motor in one direction or the other, according asthe energy or other value of the current to be measured increases ordecreases, an indicating device, and a recording device, both connectedwith, and operated by, said shaft.

16. In an electrical measuring instrument, a movable part acted upon bythe current, a spring connected thereto for overcoming the torque of thesame and for maintaining said movable part normally at its zero-point, ashaft thrown into operation by an increase in the energy or other valueof the current to be measured and longitudinally-movable means 011 saidshaft for increasing and decreasing the tension of said spring.

17. In an electrical measuring instrument, a movable part acted upon bythe current, a spring connected thereto for overcoming the torque of thesame and for maintaining said movable part normally at its zero-point, amotor, a shaft operated thereby, means thrown into operation by saidmovable part for starting said motor in one direction or the other andmeans movable longitudinally of and by said shaft for increasing ordecreas ing the tension of said spring.

18. In an electrical measuringinstrument, a movable part acted upon bythe current, a counterbalancing device for equalizing the action of thecurrent on said movable part, a reversible electric motor, a shaftoperated thereby, a connecting device movable longitudinally of saidshaft and attached to said counterbalancing device for increasing anddecreasing the tension thereof, a circuit through said motor, and meansthrown into operation by said movable part for closing the circuitthrough said motor in one direction or the other, according as theenergy or other value of the current to be measured increases ordecreases.

19. In an electrical measuring instrument, a movable part acted upon bythe current, a conducting rod or arm connected with said movable partand operated thereby, electric contacts between which said rod ismounted, a counter-balancing device for equalizing the action of thecurrent on said movable part and thereby normally maintaining saidmovable part at its zero position and said rod at a point intermediatesaid contacts, a reversible electric motor, a shaft operated thereby, aconnecting device longitudinally movable on said shaft and attached tosaid counterbalancing device for increasing and decreasing the tensionthereof, and a circuit through said motor adapted to be closed in onedirection or the other by the engagement of said rod with one or theother of said contacts as the energyor other value of the currentthrough the instrument increases or decreases.

20. In an electrical measuringinstrument, a movable part acted upon bythe current, a conducting rod or arm connected with said movable partand operated thereby, electric contacts between which said rod ismounted, a counter-balancing device for equalizing the action of thecurrent on said movable part and thereby normally maintaining saidmovable part at its zero position and said rod at a point intermediatesaid contacts, areversible electric motor, a shaft operated thereby, aconnecting device movable longitudinally of and by said shaft andattached to said counter-balancing device for increasing and decreasingthe tension thereof, a circuit through said motor adapted to be closedin one direction or the other by the engagement of said rod with one orthe other of said contacts as the energy or other value of the currentthrough the instrument increases or decreases, and indicating mechanismconnected with, and operated by, said motor.

21. In an electrical measuringinstrument, a movable part acted upon bythe current, a conducting rod or arm connected with said movable partand operated thereby, electric contacts between which said rod ismounted,

a counterbalancing device for equalizing the action of the current onsaid movable part and thereby normally maintaining said movable part atits zero position and said rod at a point intermediate said contacts, areversible electric motor, a shaft operated thereby, a connecting devicemovable longitudinally of and by said shaft and attached to saidcounterbalancing device for increasing and decreasing the tensionthereof, a circuit through said motor adapted to be closed in onedirection or the other by the engagement of said rod with one'or theother of said contacts as the energy or other value of the currentthrough the instrument increases or decreases, and recording mechanismconnected with, and operated by, said motor.

In an electrical measuringinstrument, a movable part acted upon by thecurrent, a conducting rod or bar connected therewith and operatedthereby,contacts between which said rod is mounted, a counter-balancingdevice l'or equalizing the action of the current 011 said movable partand thereby normally maintaining said movable part at itszeropoint andsaid red at a point intermediate said contacts, a reversible electricmotor for increasing and decreasing the tension of said counterbalancingdevice, a shunt-circuit from the line, including the field-magnets ofsaid motor and two resistance-coils, circuit connections between saidcontacts and said shunt-circuit at points, respectively above and belowsaid coils, and circuit connections between said conducting-rod, thearmature of said motor, and said shunt-circuit, ata point intermediatesaid coils, whereby the circuit through said armature may be closed inone direction or the other by the engagement of said rod with one or theother of said contacts upon an increase or decrease in the energy orother value of the current through the instrument.

In an electricalmeasuringinstrument, a movable part acted upon-by thecurrent, a conducting rod or bar connected therewith and operatedthereby,ccntacts between which said rod is mounted, a counterbalancingdevice for equalizing the action of the current on said movable part andthereby normally maintaining said movable part at its zeropoint and saidred at a point intermediate said contacts, a reversible electric motorfor increasing and decreasing the tension of said counterbalancingdevice, a shunt-circuit from the line, including the field-magnets ofsaid motor and two resistance -coils, circuit connections between saidcontacts and said shunt-circuit at points respectively above and belowsaid coils, circuit connections between said conducting-rod, thearmature of said motor, and said Sl1Ll11i3-Gil'O11llJ,Z-tl12t pointintermediate said coils, whereby the circuit through said armature maybe closed in one direction or the other by the engagement of said rodwith one or the other of said contacts upon an increase or decrease inthe energy or other value of the currentthrough the instrument, andindicating mechanism connected with and operated by said motor.

2t. In an electrical measuringinstrument, a movable part acted upon bythe current, a conducting rod or bar connected therewith and operatedthereby,contacts between which said rod is mounted, a couuterbalancingdcvice for equalizing the action of the current on said movable part andthereby normally maintaining said movable part at its zeropoint and saidred at a point intermediate said contacts, a reversible electric motorfor increasing and decreasing the tension of said counterbalancingdevice, a shunt-circuit from the line, including the field-magnets ofsaid motor and two resistance-coils, circuit connections between saidcontacts and said shunt-circuit at points respectively above and belowsaid coils, circuit connections between said conducting-rod, thearmature of said motor, and said shun t-circuit, ata point intermediatesaid coils, whereby the circuit through said armature may be closed inone direction or the other by the engagement of said rod with one or theother of said contacts upon an increase or decrease in the energy orother value of the current through the instrument, and recordingmechanism connected with, and operated by, said motor.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

VITTORIO ARCIONI. lVitnesses:

finonto Iirri, ll'iit'onizo CIRONE.

